The present invention relates to a parts feeder for supplying parts or components stored as arrays in magazines.
Most specially shaped electronic parts or components such as coils, switches, connectors or the like which are available in the market are generally stored as arrays in magazines.
FIG. 12 of the accompanying drawings illustrates one typical parts feeder for supplying such electronic parts stored in magazines to insert them on a printed circuit board. Parts 100 are stored as an array in an elongate magazine 101, and a stack of such magazines 101 is accommodated in a vertically elongate magazine unit 102. Therefore, parts 100 of one type are stored in one magazine unit 102. A plurality of magazine units 102 that are placed side by side is securely mounted on a supply unit 103, which is movable in a horizontal plane for selectively delivering desired parts 100 to an insertion head 105 which inserts the parts 100 into a printed-circuit board 104.
With the above arrangement, however, when the magazines 101 in one magazine unit 102 run short of the stored parts 100, the supply unit 103 must be stopped to supply the empty magazines 101 with new parts 100. Since there are as many types of stored parts as the number of the magazine units 102, the magazine units 102 must be supplied with new parts as many times as the number of the magazine units 102. Furthermore, parts 100 of different types may be of different lengths; parts of one type may be ten times longer than parts of another type. As a consequence, the number of parts that can be stored in one magazine unit 102 may be different from the number of parts that can be stored in another magazine unit 102. In addition, inasmuch as more parts 100 of one type may be inserted into the printed-circuit board 104 than parts 100 of another type, the rates at which parts 100 of different designs are dispensed from different magazine units 102 may vary from each other. For the reasons described above, the magazine units 102 tend to run short of their parts 100 at different times, and hence the supply unit 103 must be stopped at frequent intervals for parts replenishment. This is disadvantageous in that the downtime of the assembling machine associated with the supply unit 103 is increased.